Affymetrix's ( AFFX) bottom line went from black to red in the second quarter on slowing sales and rising costs. The biotech company's results fell far short of analysts' estimates, and Affymetrix's stock got pummeled after the report. In recent after-hours trading, the company's shares were off $1.57, or 7.3%, to $20. In the just-completed period, Affymetrix lost $10.2 million, or 15 cents a share. In contrast, the company earned $7.8 million or 12 cents a share, a year ago. Total revenue fell 5% year over year to $80.1 million because of a sharp slowdown in product sales. Also weighing on the company's bottom line were increased product costs and rising expenses in marketing, administrative and research-and-development areas. The GeneChip maker's just-completed results also include costs for stock options, which were not factored into the year-earlier results. Excluding those costs, Affymetrix would have lost $6.2 million, or 9 cents a share. Including those options costs, analysts polled by Thomson First Call were expecting the company to lose a penny a share on total revenue of $88.7 million. The company did not immediately provide its outlook for the third quarter. Prior to its report, analysts had forecast that the company would earn 8 cents a share on $95.1 million in the current period.